High-resolution X-ray diffraction investigation of crystal perfection and relaxation of GaAs/InGaAs/GaAs quantum wells depending on MOVPE growth conditions

1997 ◽  
Vol 19 (2-4) ◽  
pp. 369-376 ◽  
Author(s):  
U. Zeimer ◽  
F. Bugge ◽  
S. Gramlich ◽  
I. Urban ◽  
A. Oster ◽  
...  
Keyword(s):  
High Resolution ◽  
Quantum Wells ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Perfection ◽  
Movpe Growth

Four Stages of Defect Creation in Epitaxial Structures: High Resolution X-Ray Diffraction and Transmission Electron Microscopy Characterization

2012 ◽  
Author(s):  
Nikolai N. Faleev ◽  
Christiana B. Honsberg ◽  
David J. Smith
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Epitaxial Growth ◽  
Elastic Stress ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Perfection ◽  
Transmission Electron

Abstract Different epitaxial structures have been studied by high-resolution x-ray diffraction and x-ray topography, Transmission Electron Microscopy and Atomic Force Microscopy to establish correlations between epitaxial growth conditions and crystal perfection. It was confirmed that epitaxial growth under initial elastic stress inevitably leads to the creation of extended crystal defects like dislocation loops and edge dislocations in the volume of epitaxial structures, which strongly affect crystal perfection and physical properties of future devices. It was found that the type of created defects, their density and spatial distribution strongly depended on growth conditions: the value and sign of the initial elastic strain, the elastic constants of solid solutions, the temperature of deposition and growth rate, and the thickness of the epitaxial layers. All of the investigated structures were classified by their crystal perfection, using the volume density of extended defects as a parameter. It was found that the accommodation and relaxation of initial elastic stress and creation of crystal defect were up to four stages “chain” processes, necessary to stabilize the crystal structure at a level corresponding to the deterioration power of particular growth conditions.

Synchrotron white beam x-ray topography (SWBXT) and high resolution triple axis diffraction studies on AlN layers grown on 4H- and 6H-SiC seeds

2004 ◽  
Vol 831 ◽  
Author(s):  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
Rafael Dalmau ◽  
Raoul Schlesser ◽  
Zlatko Sitar
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Large Diameter ◽  
Laser Diodes ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
White Beam ◽  
Strain Data ◽  
Growth Experiments

ABSTRACTFor nitride based devices such as LEDs, high power FETs and laser diodes, single crystal substrates of AlN are highly desirable. While the sublimation technique is suitable for growing bulk AlN crystals, appropriate seeds are also necessary for growing large diameter oriented boules. 4H- and 6H-SiC substrates which are readily available commercially can potentially be implemented as seeds for bulk AlN growth. However, issues regarding SiC decomposition at high temperatures, thermal expansion mismatch, single crystal growth, etc. need to be addressed. Towards this end, a series of growth experiments have been carried out in a resistively heated reactor using on and off-axis 4H- and 6H-SiC substrates as seeds for AlN growth from the vapor phase. Several hundred microns thick AlN layers have been grown under different growth conditions. Synchrotron white beam x-ray topography (SWBXT) has been used to map the defect distribution in the grown layers and high resolution triple axis x-ray diffraction (HRTXD) experiments were carried out to record reciprocal space maps from which tilt, mismatch and strain data can be obtained. These results are analyzed with respect to the growth conditions in order to gain a better understanding of this growth process.

Microarea Strain Analysis in InGaN/GaN Multiple Quantum Wells onm-Plane Using High-Resolution Microbeam X-ray Diffraction

2013 ◽  
Vol 52 (7R) ◽  
pp. 071001
Author(s):  
Shunji Yoshida ◽  
Toshiya Yokogawa ◽  
Yasuhiko Imai ◽  
Shigeru Kimura
Keyword(s):  
High Resolution ◽  
Quantum Wells ◽  
Strain Analysis ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
X Ray

Characterization of strained quantum wells by high‐resolution x‐ray diffraction

1996 ◽  
Vol 79 (4) ◽  
pp. 1869-1875 ◽  
Author(s):  
Y. Finkelstein ◽  
E. Zolotoyabko ◽  
M. Blumina ◽  
D. Fekete
Keyword(s):  
High Resolution ◽  
Quantum Wells ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strained Quantum Wells

High Resolution X-ray Diffraction Analysis of GaN-Based Heterostructures Grown by OMVPE

1996 ◽  
Vol 449 ◽  
Author(s):  
M.S. Goorsky ◽  
A.Y. Polyakov ◽  
M. Skowronski ◽  
M. Shin ◽  
D.W. Greve
Keyword(s):  
High Resolution ◽  
Dislocation Density ◽  
Layer Thickness ◽  
Vapor Phase ◽  
Edge Dislocation ◽  
Initial Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Perfection ◽  
Misorientation Angles

ABSTRACTWe demonstrate the use of triple axis diffraction measurements, including Φ scans (in which the sample is rotated about an axis perpendicular to its surface) to assess the crystal perfection of wurtzite GaN layers on sapphire grown using different pre-nitridation growth treatments by or-ganometallic vapor phase epitaxy. The Φ scans determine the in-plane misorientation angles between the crystallites and hence provide information on the edge dislocation density. Using glancing incidence (1014) and (1015) reflections, we determined that the misorientation among the GaN crystallites decreases with increasing layer thickness and that the pre-nitridation conditions control the initial level of misorientation. Triple axis ω and ω-2θ scans around the (0002) reflection did not show a systematic trend with increasing layer thickness. However, layers grown without a pre-nitridation step tended to exhibit higher values of both mosaic spread and strain. The appropriate asymmetric reflections for GaN-based Φ scan measurements are determined using structure factor calculations, which are presented here.

High Resolution X-ray Diffraction Characterization of [111]B Oriented InGaAs/GaAs Mqw Structures

1995 ◽  
Vol 39 ◽  
pp. 439-448
Author(s):  
A Sanz-Hervas ◽  
A Sacedón ◽  
E.J Abril ◽  
J.L Sanchez-Rojas ◽  
C. Villar ◽  
...  
Keyword(s):  
High Resolution ◽  
Quantum Well ◽  
Structural Information ◽  
Multiple Quantum Well ◽  
Growth Conditions ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Quantum Well Structures ◽  
X Ray

In this work we apply high-resolution X-ray diffractometry to the study of InGaAs/GaAs multiple quantum well structures on (001) and(lll)B GaAs substrates. The samples consisted of p-i-n diodes with a multiple quantum well embedded in the i-region and were simultaneously grown on (001) and (111)B substrates by molecular beam epitaxy. For the characterization we have used symmetric and asymmetric reflections at different azimuthal positions. The interpretation of the diffraction profiles has been possible thanks to our recently developed simulation model, which allows the calculation of any reflection regardless of the substrate orientation. X-ray results about composition and thickness are very similar in the samples simultaneously grown on both orientations as expected from our specific growth conditions. The information obtained from X-ray characterization is consistent with the results of photoluminescence and photocurrent measurements within the experimental uncertainty of the techniques. In (lll)B samples, X-ray diffractometry provides structural information which cannot be easily obtained from optical characterization techniques.

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